Block Themes: Add section styling via extended block style variations

Provide users with the ability to style entire sections of a page without
having to tediously reapply the same sets of styles.

This is done by extending block style variations to apply to nested blocks.

See https://github.com/WordPress/gutenberg/pull/57908.

Fixes #61312.
Props aaronrobertshaw, talldanwp, ramonopoly, isabel_brison, andrewserong.

Built from https://develop.svn.wordpress.org/trunk@58264


git-svn-id: http://core.svn.wordpress.org/trunk@57727 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/block-supports/block-style-variations.php

@@ -0,0 +1,424 @@
+<?php
+/**
+ * Block support to enable per-section styling of block types via
+ * block style variations.
+ *
+ * @package WordPress
+ * @since 6.6.0
+ */
+
+/**
+ * Generate block style variation instance name.
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param array  $block     Block object.
+ * @param string $variation Slug for the block style variation.
+ *
+ * @return string The unique variation name.
+ */
+function wp_create_block_style_variation_instance_name( $block, $variation ) {
+	return $variation . '--' . md5( serialize( $block ) );
+}
+
+/**
+ * Determines the block style variation names within a CSS class string.
+ *
+ * @since 6.6.0
+ *
+ * @param string $class_string CSS class string to look for a variation in.
+ *
+ * @return array|null The block style variation name if found.
+ */
+function wp_get_block_style_variation_name_from_class( $class_string ) {
+	if ( ! is_string( $class_string ) ) {
+		return null;
+	}
+
+	preg_match_all( '/\bis-style-(?!default)(\S+)\b/', $class_string, $matches );
+	return $matches[1] ?? null;
+}
+
+/**
+ * Render the block style variation's styles.
+ *
+ * In the case of nested blocks with variations applied, we want the parent
+ * variation's styles to be rendered before their descendants. This solves the
+ * issue of a block type being styled in both the parent and descendant: we want
+ * the descendant style to take priority, and this is done by loading it after,
+ * in the DOM order. This is why the variation stylesheet generation is in a
+ * different filter.
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param array $parsed_block The parsed block.
+ *
+ * @return array The parsed block with block style variation classname added.
+ */
+function wp_render_block_style_variation_support_styles( $parsed_block ) {
+	$classes    = $parsed_block['attrs']['className'] ?? null;
+	$variations = wp_get_block_style_variation_name_from_class( $classes );
+
+	if ( ! $variations ) {
+		return $parsed_block;
+	}
+
+	$tree       = WP_Theme_JSON_Resolver::get_merged_data();
+	$theme_json = $tree->get_raw_data();
+
+	// Only the first block style variation with data is supported.
+	$variation_data = array();
+	foreach ( $variations as $variation ) {
+		$variation_data = $theme_json['styles']['blocks'][ $parsed_block['blockName'] ]['variations'][ $variation ] ?? array();
+
+		if ( ! empty( $variation_data ) ) {
+			break;
+		}
+	}
+
+	if ( empty( $variation_data ) ) {
+		return $parsed_block;
+	}
+
+	$variation_instance = wp_create_block_style_variation_instance_name( $parsed_block, $variation );
+	$class_name         = "is-style-$variation_instance";
+	$updated_class_name = $parsed_block['attrs']['className'] . " $class_name";
+
+	/*
+	 * Even though block style variations are effectively theme.json partials,
+	 * they can't be processed completely as though they are.
+	 *
+	 * Block styles support custom selectors to direct specific types of styles
+	 * to inner elements. For example, borders on Image block's get applied to
+	 * the inner `img` element rather than the wrapping `figure`.
+	 *
+	 * The following relocates the "root" block style variation styles to
+	 * under an appropriate blocks property to leverage the preexisting style
+	 * generation for simple block style variations. This way they get the
+	 * custom selectors they need.
+	 *
+	 * The inner elements and block styles for the variation itself are
+	 * still included at the top level but scoped by the variation's selector
+	 * when the stylesheet is generated.
+	 */
+	$elements_data = $variation_data['elements'] ?? array();
+	$blocks_data   = $variation_data['blocks'] ?? array();
+	unset( $variation_data['elements'] );
+	unset( $variation_data['blocks'] );
+
+	_wp_array_set(
+		$blocks_data,
+		array( $parsed_block['blockName'], 'variations', $variation_instance ),
+		$variation_data
+	);
+
+	$config = array(
+		'version' => WP_Theme_JSON::LATEST_SCHEMA,
+		'styles'  => array(
+			'elements' => $elements_data,
+			'blocks'   => $blocks_data,
+		),
+	);
+
+	// Turn off filter that excludes block nodes. They are needed here for the variation's inner block types.
+	if ( ! is_admin() ) {
+		remove_filter( 'wp_theme_json_get_style_nodes', 'wp_filter_out_block_nodes' );
+	}
+
+	// Temporarily prevent variation instance from being sanitized while processing theme.json.
+	$styles_registry = WP_Block_Styles_Registry::get_instance();
+	$styles_registry->register( $parsed_block['blockName'], array( 'name' => $variation_instance ) );
+
+	$variation_theme_json = new WP_Theme_JSON( $config, 'blocks' );
+	$variation_styles     = $variation_theme_json->get_stylesheet(
+		array( 'styles' ),
+		array( 'custom' ),
+		array(
+			'skip_root_layout_styles' => true,
+			'scope'                   => ".$class_name",
+		)
+	);
+
+	// Clean up temporary block style now instance styles have been processed.
+	$styles_registry->unregister( $parsed_block['blockName'], $variation_instance );
+
+	// Restore filter that excludes block nodes.
+	if ( ! is_admin() ) {
+		add_filter( 'wp_theme_json_get_style_nodes', 'wp_filter_out_block_nodes' );
+	}
+
+	if ( empty( $variation_styles ) ) {
+		return $parsed_block;
+	}
+
+	wp_register_style( 'block-style-variation-styles', false, array( 'global-styles', 'wp-block-library' ) );
+	wp_add_inline_style( 'block-style-variation-styles', $variation_styles );
+
+	/*
+	 * Add variation instance class name to block's className string so it can
+	 * be enforced in the block markup via render_block filter.
+	 */
+	_wp_array_set( $parsed_block, array( 'attrs', 'className' ), $updated_class_name );
+
+	return $parsed_block;
+}
+
+/**
+ * Ensure the variation block support class name generated and added to
+ * block attributes in the `render_block_data` filter gets applied to the
+ * block's markup.
+ *
+ * @see wp_render_block_style_variation_support_styles
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param  string $block_content Rendered block content.
+ * @param  array  $block         Block object.
+ *
+ * @return string                Filtered block content.
+ */
+function wp_render_block_style_variation_class_name( $block_content, $block ) {
+	if ( ! $block_content || empty( $block['attrs']['className'] ) ) {
+		return $block_content;
+	}
+
+	/*
+	 * Matches a class prefixed by `is-style`, followed by the
+	 * variation slug, then `--`, and finally a hash.
+	 *
+	 * See `wp_create_block_style_variation_instance_name` for class generation.
+	 */
+	preg_match( '/\bis-style-(\S+?--\w+)\b/', $block['attrs']['className'], $matches );
+
+	if ( empty( $matches ) ) {
+		return $block_content;
+	}
+
+	$tags = new WP_HTML_Tag_Processor( $block_content );
+
+	if ( $tags->next_tag() ) {
+		/*
+		 * Ensure the variation instance class name set in the
+		 * `render_block_data` filter is applied in markup.
+		 * See `wp_render_block_style_variation_support_styles`.
+		 */
+		$tags->add_class( $matches[0] );
+	}
+
+	return $tags->get_updated_html();
+}
+
+/**
+ * Collects block style variation data for merging with theme.json data.
+ * As each block style variation is processed it is registered if it hasn't
+ * been already. This registration is required for later sanitization of
+ * theme.json data.
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param array $variations Shared block style variations.
+ *
+ * @return array Block variations data to be merged under `styles.blocks`.
+ */
+function wp_resolve_and_register_block_style_variations( $variations ) {
+	$variations_data = array();
+
+	if ( empty( $variations ) ) {
+		return $variations_data;
+	}
+
+	$registry              = WP_Block_Styles_Registry::get_instance();
+	$have_named_variations = ! wp_is_numeric_array( $variations );
+
+	foreach ( $variations as $key => $variation ) {
+		$supported_blocks = $variation['blockTypes'] ?? array();
+
+		/*
+		 * Standalone theme.json partial files for block style variations
+		 * will have their styles under a top-level property by the same name.
+		 * Variations defined within an existing theme.json or theme style
+		 * variation will themselves already be the required styles data.
+		 */
+		$variation_data = $variation['styles'] ?? $variation;
+
+		if ( empty( $variation_data ) ) {
+			continue;
+		}
+
+		/*
+		 * Block style variations read in via standalone theme.json partials
+		 * need to have their name set to the kebab case version of their title.
+		 */
+		$variation_name  = $have_named_variations ? $key : _wp_to_kebab_case( $variation['title'] );
+		$variation_label = $variation['title'] ?? $variation_name;
+
+		foreach ( $supported_blocks as $block_type ) {
+			$registered_styles = $registry->get_registered_styles_for_block( $block_type );
+
+			// Register block style variation if it hasn't already been registered.
+			if ( ! array_key_exists( $variation_name, $registered_styles ) ) {
+				register_block_style(
+					$block_type,
+					array(
+						'name'  => $variation_name,
+						'label' => $variation_label,
+					)
+				);
+			}
+
+			// Add block style variation data under current block type.
+			$path = array( $block_type, 'variations', $variation_name );
+			_wp_array_set( $variations_data, $path, $variation_data );
+		}
+	}
+
+	return $variations_data;
+}
+
+/**
+ * Merges variations data with existing theme.json data ensuring that the
+ * current theme.json data values take precedence.
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param array              $variations_data Block style variations data keyed by block type.
+ * @param WP_Theme_JSON_Data $theme_json      Current theme.json data.
+ * @param string             $origin          Origin for the theme.json data.
+ *
+ * @return WP_Theme_JSON The merged theme.json data.
+ */
+function wp_merge_block_style_variations_data( $variations_data, $theme_json, $origin = 'theme' ) {
+	if ( empty( $variations_data ) ) {
+		return $theme_json;
+	}
+
+	$variations_theme_json_data = array(
+		'version' => WP_Theme_JSON::LATEST_SCHEMA,
+		'styles'  => array( 'blocks' => $variations_data ),
+	);
+
+	$variations_theme_json = new WP_Theme_JSON_Data( $variations_theme_json_data, $origin );
+
+	/*
+	 * Merge the current theme.json data over shared variation data so that
+	 * any explicit per block variation values take precedence.
+	 */
+	return $variations_theme_json->update_with( $theme_json->get_data() );
+}
+
+/**
+ * Merges any shared block style variation definitions from a theme style
+ * variation into their appropriate block type within theme json styles. Any
+ * custom user selections already made will take precedence over the shared
+ * style variation value.
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param WP_Theme_JSON_Data $theme_json Current theme.json data.
+ *
+ * @return WP_Theme_JSON_Data
+ */
+function wp_resolve_block_style_variations_from_theme_style_variation( $theme_json ) {
+	$theme_json_data   = $theme_json->get_data();
+	$shared_variations = $theme_json_data['styles']['blocks']['variations'] ?? array();
+	$variations_data   = wp_resolve_and_register_block_style_variations( $shared_variations );
+
+	return wp_merge_block_style_variations_data( $variations_data, $theme_json, 'user' );
+}
+
+/**
+ * Merges block style variation data sourced from standalone partial
+ * theme.json files.
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param WP_Theme_JSON_Data $theme_json Current theme.json data.
+ *
+ * @return WP_Theme_JSON_Data
+ */
+function wp_resolve_block_style_variations_from_theme_json_partials( $theme_json ) {
+	$block_style_variations = WP_Theme_JSON_Resolver::get_style_variations( 'block' );
+	$variations_data        = wp_resolve_and_register_block_style_variations( $block_style_variations );
+
+	return wp_merge_block_style_variations_data( $variations_data, $theme_json );
+}
+
+/**
+ * Merges shared block style variations registered within the
+ * `styles.blocks.variations` property of the primary theme.json file.
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param WP_Theme_JSON_Data $theme_json Current theme.json data.
+ *
+ * @return WP_Theme_JSON_Data
+ */
+function wp_resolve_block_style_variations_from_primary_theme_json( $theme_json ) {
+	$theme_json_data        = $theme_json->get_data();
+	$block_style_variations = $theme_json_data['styles']['blocks']['variations'] ?? array();
+	$variations_data        = wp_resolve_and_register_block_style_variations( $block_style_variations );
+
+	return wp_merge_block_style_variations_data( $variations_data, $theme_json );
+}
+
+/**
+ * Merges block style variations registered via the block styles registry with a
+ * style object, under their appropriate block types within theme.json styles.
+ * Any variation values defined within the theme.json specific to a block type
+ * will take precedence over these shared definitions.
+ *
+ * @since 6.6.0
+ * @access private
+ *
+ * @param WP_Theme_JSON_Data $theme_json Current theme.json data.
+ *
+ * @return WP_Theme_JSON_Data
+ */
+function wp_resolve_block_style_variations_from_styles_registry( $theme_json ) {
+	$registry        = WP_Block_Styles_Registry::get_instance();
+	$styles          = $registry->get_all_registered();
+	$variations_data = array();
+
+	foreach ( $styles as $block_type => $variations ) {
+		foreach ( $variations as $variation_name => $variation ) {
+			if ( ! empty( $variation['style_data'] ) ) {
+				$path = array( $block_type, 'variations', $variation_name );
+				_wp_array_set( $variations_data, $path, $variation['style_data'] );
+			}
+		}
+	}
+
+	return wp_merge_block_style_variations_data( $variations_data, $theme_json );
+}
+
+/**
+ * Enqueues styles for block style variations.
+ *
+ * @since 6.6.0
+ * @access private
+ */
+function wp_enqueue_block_style_variation_styles() {
+	wp_enqueue_style( 'block-style-variation-styles' );
+}
+
+// Register the block support.
+WP_Block_Supports::get_instance()->register( 'block-style-variation', array() );
+
+add_filter( 'render_block_data', 'wp_render_block_style_variation_support_styles', 10, 2 );
+add_filter( 'render_block', 'wp_render_block_style_variation_class_name', 10, 2 );
+add_action( 'wp_enqueue_scripts', 'wp_enqueue_block_style_variation_styles', 1 );
+
+// Resolve block style variations from all their potential sources. The order here is deliberate.
+add_filter( 'wp_theme_json_data_theme', 'wp_resolve_block_style_variations_from_primary_theme_json', 10, 1 );
+add_filter( 'wp_theme_json_data_theme', 'wp_resolve_block_style_variations_from_theme_json_partials', 10, 1 );
+add_filter( 'wp_theme_json_data_theme', 'wp_resolve_block_style_variations_from_styles_registry', 10, 1 );
+
+add_filter( 'wp_theme_json_data_user', 'wp_resolve_block_style_variations_from_theme_style_variation', 10, 1 );

wp-includes/class-wp-theme-json-resolver.php

@@ -701,16 +701,46 @@ class WP_Theme_JSON_Resolver {
 		return $nested_json_files;
 	}
 
+	/**
+	 * Determines if a supplied style variation matches the provided scope.
+	 *
+	 * For backwards compatibility, if a variation does not define any scope
+	 * related property, e.g. `blockTypes`, it is assumed to be a theme style
+	 * variation.
+	 *
+	 * @since 6.6.0
+	 *
+	 * @param array  $variation Theme.json shaped style variation object.
+	 * @param string $scope     Scope to check e.g. theme, block etc.
+	 *
+	 * @return boolean
+	 */
+	private static function style_variation_has_scope( $variation, $scope ) {
+		if ( 'block' === $scope ) {
+			return isset( $variation['blockTypes'] );
+		}
+
+		if ( 'theme' === $scope ) {
+			return ! isset( $variation['blockTypes'] );
+		}
+
+		return false;
+	}
 
 	/**
 	 * Returns the style variations defined by the theme.
 	 *
 	 * @since 6.0.0
 	 * @since 6.2.0 Returns parent theme variations if theme is a child.
+	 * @since 6.6.0 Added configurable scope parameter to allow filtering
+	 *              theme.json partial files by the scope to which they
+	 *              can be applied e.g. theme vs block etc.
+	 *
+	 * @param string $scope The scope or type of style variation to retrieve e.g. theme, block etc.
 	 *
 	 * @return array
 	 */
-	public static function get_style_variations() {
+	public static function get_style_variations( $scope = 'theme' ) {
 		$variation_files    = array();
 		$variations         = array();
 		$base_directory     = get_stylesheet_directory() . '/styles';
@@ -733,7 +763,7 @@ class WP_Theme_JSON_Resolver {
 		ksort( $variation_files );
 		foreach ( $variation_files as $path => $file ) {
 			$decoded_file = wp_json_file_decode( $path, array( 'associative' => true ) );
-			if ( is_array( $decoded_file ) ) {
+			if ( is_array( $decoded_file ) && static::style_variation_has_scope( $decoded_file, $scope ) ) {
 				$translated = static::translate( $decoded_file, wp_get_theme()->get( 'TextDomain' ) );
 				$variation  = ( new WP_Theme_JSON( $translated ) )->get_raw_data();
 				if ( empty( $variation['title'] ) ) {

wp-includes/class-wp-theme-json.php

@@ -346,9 +346,11 @@ class WP_Theme_JSON {
 	 * @since 5.9.0 Renamed from `ALLOWED_TOP_LEVEL_KEYS` to `VALID_TOP_LEVEL_KEYS`,
 	 *              added the `customTemplates` and `templateParts` values.
 	 * @since 6.3.0 Added the `description` value.
+	 * @since 6.6.0 Added `blockTypes` to support block style variation theme.json partials.
 	 * @var string[]
 	 */
 	const VALID_TOP_LEVEL_KEYS = array(
+		'blockTypes',
 		'customTemplates',
 		'description',
 		'patterns',
@@ -823,6 +825,7 @@ class WP_Theme_JSON {
 	 * @since 5.8.0
 	 * @since 5.9.0 Added the `$valid_block_names` and `$valid_element_name` parameters.
 	 * @since 6.3.0 Added the `$valid_variations` parameter.
+	 * @since 6.6.0 Updated schema to allow extended block style variations.
 	 *
 	 * @param array $input               Structure to sanitize.
 	 * @param array $valid_block_names   List of valid block names.
@@ -881,6 +884,27 @@ class WP_Theme_JSON {
 
 		$schema_styles_blocks   = array();
 		$schema_settings_blocks = array();
+
+		/*
+		 * Generate a schema for blocks.
+		 * - Block styles can contain `elements` & `variations` definitions.
+		 * - Variations definitions cannot be nested.
+		 * - Variations can contain styles for inner `blocks`.
+		 * - Variation inner `blocks` styles can contain `elements`.
+		 *
+		 * As each variation needs a `blocks` schema but further nested
+		 * inner `blocks`, the overall schema will be generated in multiple passes.
+		 */
+		foreach ( $valid_block_names as $block ) {
+			$schema_settings_blocks[ $block ]           = static::VALID_SETTINGS;
+			$schema_styles_blocks[ $block ]             = $styles_non_top_level;
+			$schema_styles_blocks[ $block ]['elements'] = $schema_styles_elements;
+		}
+
+		$block_style_variation_styles             = static::VALID_STYLES;
+		$block_style_variation_styles['blocks']   = $schema_styles_blocks;
+		$block_style_variation_styles['elements'] = $schema_styles_elements;
+
 		foreach ( $valid_block_names as $block ) {
 			// Build the schema for each block style variation.
 			$style_variation_names = array();
@@ -897,12 +921,9 @@ class WP_Theme_JSON {
 
 			$schema_styles_variations = array();
 			if ( ! empty( $style_variation_names ) ) {
-				$schema_styles_variations = array_fill_keys( $style_variation_names, $styles_non_top_level );
+				$schema_styles_variations = array_fill_keys( $style_variation_names, $block_style_variation_styles );
 			}
 
-			$schema_settings_blocks[ $block ]             = static::VALID_SETTINGS;
-			$schema_styles_blocks[ $block ]               = $styles_non_top_level;
-			$schema_styles_blocks[ $block ]['elements']   = $schema_styles_elements;
 			$schema_styles_blocks[ $block ]['variations'] = $schema_styles_variations;
 		}
 
@@ -913,6 +934,12 @@ class WP_Theme_JSON {
 		$schema['settings']['blocks']                     = $schema_settings_blocks;
 		$schema['settings']['typography']['fontFamilies'] = static::schema_in_root_and_per_origin( static::FONT_FAMILY_SCHEMA );
 
+		/*
+		 * Shared block style variations can be registered from the theme.json data so we can't
+		 * validate them against pre-registered block style variations.
+		 */
+		$schema['styles']['blocks']['variations'] = null;
+
 		// Remove anything that's not present in the schema.
 		foreach ( array( 'styles', 'settings' ) as $subtree ) {
 			if ( ! isset( $input[ $subtree ] ) ) {
@@ -1016,16 +1043,36 @@ class WP_Theme_JSON {
 	 * @since 5.9.0 Added `duotone` key with CSS selector.
 	 * @since 6.1.0 Added `features` key with block support feature level selectors.
 	 * @since 6.3.0 Refactored and stabilized selectors API.
+	 * @since 6.6.0 Updated to include block style variations from the block styles registry.
 	 *
 	 * @return array Block metadata.
 	 */
 	protected static function get_blocks_metadata() {
-		$registry = WP_Block_Type_Registry::get_instance();
+		$registry       = WP_Block_Type_Registry::get_instance();
-		$blocks   = $registry->get_all_registered();
+		$blocks         = $registry->get_all_registered();
+		$style_registry = WP_Block_Styles_Registry::get_instance();
 
 		// Is there metadata for all currently registered blocks?
 		$blocks = array_diff_key( $blocks, static::$blocks_metadata );
 		if ( empty( $blocks ) ) {
+			/*
+			 * New block styles may have been registered within WP_Block_Styles_Registry.
+			 * Update block metadata for any new block style variations.
+			 */
+			$registered_styles = $style_registry->get_all_registered();
+			foreach ( static::$blocks_metadata as $block_name => $block_metadata ) {
+				if ( ! empty( $registered_styles[ $block_name ] ) ) {
+					$style_selectors = $block_metadata['styleVariations'] ?? array();
+
+					foreach ( $registered_styles[ $block_name ] as $block_style ) {
+						if ( ! isset( $style_selectors[ $block_style['name'] ] ) ) {
+							$style_selectors[ $block_style['name'] ] = static::get_block_style_variation_selector( $block_style['name'], $block_metadata['selector'] );
+						}
+					}
+
+					static::$blocks_metadata[ $block_name ]['styleVariations'] = $style_selectors;
+				}
+			}
 			return static::$blocks_metadata;
 		}
 
@@ -1060,11 +1107,20 @@ class WP_Theme_JSON {
 			}
 
 			// If the block has style variations, append their selectors to the block metadata.
+			$style_selectors = array();
 			if ( ! empty( $block_type->styles ) ) {
-				$style_selectors = array();
 				foreach ( $block_type->styles as $style ) {
 					$style_selectors[ $style['name'] ] = static::get_block_style_variation_selector( $style['name'], static::$blocks_metadata[ $block_name ]['selector'] );
 				}
+			}
+
+			// Block style variations can be registered through the WP_Block_Styles_Registry as well as block.json.
+			$registered_styles = $style_registry->get_registered_styles_for_block( $block_name );
+			foreach ( $registered_styles as $style ) {
+				$style_selectors[ $style['name'] ] = static::get_block_style_variation_selector( $style['name'], static::$blocks_metadata[ $block_name ]['selector'] );
+			}
+
+			if ( ! empty( $style_selectors ) ) {
 				static::$blocks_metadata[ $block_name ]['styleVariations'] = $style_selectors;
 			}
 		}
@@ -1158,6 +1214,7 @@ class WP_Theme_JSON {
 	 * @since 5.8.0
 	 * @since 5.9.0 Removed the `$type` parameter, added the `$types` and `$origins` parameters.
 	 * @since 6.3.0 Add fallback layout styles for Post Template when block gap support isn't available.
+	 * @since 6.6.0 Added `skip_root_layout_styles` option to omit layout styles if desired.
 	 *
 	 * @param string[] $types   Types of styles to load. Will load all by default. It accepts:
 	 *                          - `variables`: only the CSS Custom Properties for presets & custom ones.
@@ -1165,9 +1222,10 @@ class WP_Theme_JSON {
 	 *                          - `presets`: only the classes for the presets.
 	 * @param string[] $origins A list of origins to include. By default it includes VALID_ORIGINS.
 	 * @param array    $options An array of options for now used for internal purposes only (may change without notice).
-	 *                          The options currently supported are 'scope' that makes sure all style are scoped to a
+	 *                       The options currently supported are:
-	 *                          given selector, and root_selector which overwrites and forces a given selector to be
+	 *                       - 'scope' that makes sure all style are scoped to a given selector
-	 *                          used on the root node.
+	 *                       - `root_selector` which overwrites and forces a given selector to be used on the root node
+	 *                       - `skip_root_layout_styles` which omits root layout styles from the generated stylesheet.
 	 * @return string The resulting stylesheet.
 	 */
 	public function get_stylesheet( $types = array( 'variables', 'styles', 'presets' ), $origins = null, $options = array() ) {
@@ -1220,7 +1278,7 @@ class WP_Theme_JSON {
 		}
 
 		if ( in_array( 'styles', $types, true ) ) {
-			if ( false !== $root_style_key ) {
+			if ( false !== $root_style_key && empty( $options['skip_root_layout_styles'] ) ) {
 				$stylesheet .= $this->get_root_layout_rules( $style_nodes[ $root_style_key ]['selector'], $style_nodes[ $root_style_key ] );
 			}
 			$stylesheet .= $this->get_block_classes( $style_nodes );
@@ -3114,6 +3172,7 @@ class WP_Theme_JSON {
 	 *
 	 * @since 5.9.0
 	 * @since 6.3.2 Preserves global styles block variations when securing styles.
+	 * @since 6.6.0 Updated to allow variation element styles.
 	 *
 	 * @param array $theme_json Structure to sanitize.
 	 * @return array Sanitized structure.
@@ -3175,6 +3234,29 @@ class WP_Theme_JSON {
 					}
 
 					$variation_output = static::remove_insecure_styles( $variation_input );
+
+					// Process a variation's elements and element pseudo selector styles.
+					if ( isset( $variation_input['elements'] ) ) {
+						foreach ( $valid_element_names as $element_name ) {
+							$element_input = $variation_input['elements'][ $element_name ] ?? null;
+							if ( $element_input ) {
+								$element_output = static::remove_insecure_styles( $element_input );
+
+								if ( isset( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $element_name ] ) ) {
+									foreach ( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $element_name ] as $pseudo_selector ) {
+										if ( isset( $element_input[ $pseudo_selector ] ) ) {
+											$element_output[ $pseudo_selector ] = static::remove_insecure_styles( $element_input[ $pseudo_selector ] );
+										}
+									}
+								}
+
+								if ( ! empty( $element_output ) ) {
+									_wp_array_set( $variation_output, array( 'elements', $element_name ), $element_output );
+								}
+							}
+						}
+					}
+
 					if ( ! empty( $variation_output ) ) {
 						_wp_array_set( $sanitized, $variation['path'], $variation_output );
 					}

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.6-alpha-58263';
+$wp_version = '6.6-alpha-58264';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.

wp-settings.php

@@ -366,6 +366,7 @@ require ABSPATH . WPINC . '/class-wp-block-supports.php';
 require ABSPATH . WPINC . '/block-supports/utils.php';
 require ABSPATH . WPINC . '/block-supports/align.php';
 require ABSPATH . WPINC . '/block-supports/background.php';
+require ABSPATH . WPINC . '/block-supports/block-style-variations.php';
 require ABSPATH . WPINC . '/block-supports/border.php';
 require ABSPATH . WPINC . '/block-supports/colors.php';
 require ABSPATH . WPINC . '/block-supports/custom-classname.php';